I think what I'm probably looking for is a good javascript image map tutorial. The nav bar you referenced is not actually part of a linked header image. Ideally, it would be nice to do this with CSS, but I don't think it is possible.

Jeffrey zeldman site gives you roughly the idea on how to combine image map and image rollover for navigation bar. You can check his site or mine out to sort of study the css codes on how to do this. As far as i can tell, its neat and no javascript required.